For electronic devices with optical elements, such as light-emitting diode (“LED”) devices, the optical element is typically molded with a layer of transparent or translucent molding encapsulant. In prior art molding systems for such electronic devices, the said molding encapsulant is usually molded by either dispensing the molding encapsulant into molding cavities directly or by injection molding to produce individual packages. The yields obtained by molding the optical elements using these methods are generally unsatisfactory.
More recently, compression molding has provided a viable solution for improving productivity by molding a panel of LED devices simultaneously. This form of molding involves molding a single panel of LED devices mounted on a substrate, such as a ceramic substrate, which has high heat capacity and low heat conductance. A problem that is often encountered with the molding of devices mounted on a brittle substrate such as a ceramic substrate is that the ceramic substrate holding the devices may crack during the molding procedure due to excessive clamping pressure exerted during molding. It would therefore be desirable to improve the yield from molding LED devices mounted on brittle substrates by the use of compression molding and yet reduce incidences of breakages of the brittle substrates.